Roadway or street lighting fixtures are exposed to a range of environmental factors that impact performance and longevity of lighting fixtures. Existing roadway lighting commonly uses high-intensity discharge lamps, often high pressure sodium lamps (HPS). The power supply designs have been relatively simply but the light quality, efficiency and controllability of the fixtures has been less than ideal. The introduction next generation lighting fixtures such as light emitting diode (LED) based lighting fixtures provides greater efficiency, light quality and controllability however present challenges in ensuring reliable operation for the life of the lighting fixture. Factors such as thermal control, power efficiency, current regulation and packaging constraints must be accounted for to meet operation requirements. The temperature extremes and packaging restraints require an efficient design to ensure reliability. Providing a power supply that meets the demanding design requirements and cope with environmental extremes has not to date been achievable. In addition, single-ended primary inductance converters (SEPIC) have only been utilized in single channel configurations due to interference between channels.
Accordingly, apparatus and methods that enable an improved LED power supply remains highly desirable.